Project Summary/Abstract This investigation will adapt and pilot test an integrated health risk-reduction and motivational enhancement intervention for Juvenile Justice (JJ) youth that will ultimately be (after full testing through a subsequent large- scale RCT) a sustainable intervention implemented within a JJ supervision/case management context to teach and facilitate positive, prosocial, and expected behaviors. The intervention will use graphical approaches to encourage introspection and problem identification, enhance self-regulation, improve analytical problem- solving skills, and promote healthy behaviors in two inter-related target areas: substance use and risky sex practices. Existing evidence-based intervention materials will be incorporated and delivered through a web- based application. Sessions will be self-directed (require minimal instruction/interaction assistance), and also include a service referral piece whereby youth are provided with a list of treatment and health agencies at the end of sessions that address specific topics. Research activities will be carried out in two pilot studies: (1) Intervention Adaptation and Feasibility and (2) Protocol Feasibility and Preliminary Efficacy Trial. In Pilot 1, intervention content will be adapted from existing evidence-based interventions so that it is developmentally appropriate for the target population and suitable for a web-based format (N = 30; 20 youth, 10 JJ staff). Pilot 2 will test a scaled-down version of an intervention efficacy randomized control trial (RCT), comparing the web- based intervention to a time-matched, information-only group using a 2-arm, randomized design (whereby 120 enrolled youth from one juvenile probation department are randomly assigned to condition). The specific aims of the proposed investigation are to examine intervention feasibility and acceptability, test the feasibility of the study protocol (adherence, subject retention, instrumentation) with JJ-involved youth, and examine the preliminary efficacy of the intervention for addressing health-related behavior change. Proximal outcomes will be improvements in change mechanisms (e.g., problem recognition, decision making, intention to reduce personal risk) and service initiation (SU or STI-related services). Distal outcomes will be reduction in risky behaviors, including substance use (self-report and urinalysis) and sexual health risk (self-reported risky sex practices). Research questions and preliminary hypotheses are specified, and successful completion of the aims will result in an intervention that is appropriate and feasible for use with JJ-involved youth, provide important information regarding feasibility of a full-scale RCT, inform future study design (and a subsequent R01 application), and provide preliminary information regarding the efficacy of the intervention. The study has considerable potential to address an important vulnerable population?justice-involved youth?and focusses on a significant problem?youth behaviors that are self-detrimental and unhealthy.